<template>
  <div class="swiper-container"  ref="cur">
    <div class="swiper-wrapper">
      <div class="swiper-slide" v-for="(slide,index) of this.skuImageList" :key="slide.id" >
        <img :src="slide.imgUrl" :class="{active:currentIndex==index}" @click="changeCurrentIndex(index)">
      </div>
    </div>
    <div class="swiper-button-next"></div>
    <div class="swiper-button-prev"></div>
  </div>
</template>

<script>

  import Swiper from 'swiper'
  export default {
    name: "ImageList",
    props:['skuImageList'],
    data(){
      return{
        currentIndex:0
      }
    },
    watch: {
        skuImageList: {
            // 立即监听：不管你数据有没有变化，上来就立即监听一次
            // 为什么watch监听不到list:因为这个数据从来都没有发生变化（数据是父亲给的，给的时候就是一个对象，对象里面由数据）
            immediate: true,
            handler() {
                // 只能监听到数据已经有了，但是v-for动态渲染结构我们还没有办法确定，因此还是需要用nextTick
                this.$nextTick(() => {
                    new Swiper(
                        this.$refs.cur,
                        {
                            navigation: {
                                nextEl: ".swiper-button-next",
                                prevEl: ".swiper-button-prev",
                            },
                            slidesPerView:3,
                            slidesPerGroup:1
                        }
                    );
                })
            }
        }
    },
    methods:{
      changeCurrentIndex(index){
        // 当前活动边框改变
        this.currentIndex=index;
        // 将当前下标传递给兄弟组件Zoom去显示当前的大图
        this.$bus.$emit('getIndex',index);
      }
    },
  }
</script>

<style lang="less" scoped>
  .swiper-container {
    height: 56px;
    width: 412px;
    box-sizing: border-box;
    padding: 0 12px;

    .swiper-slide {
      width: 56px;
      height: 56px;

      img {
        width: 100%;
        height: 100%;
        border: 1px solid #ccc;
        padding: 2px;
        width: 50px;
        height: 50px;
        display: block;

        &.active {
          border: 2px solid #f60;
          padding: 1px;
        }
      }
    }

    .swiper-button-next {
      left: auto;
      right: 0;
    }

    .swiper-button-prev {
      left: 0;
      right: auto;
    }

    .swiper-button-next,
    .swiper-button-prev {
      box-sizing: border-box;
      width: 12px;
      height: 56px;
      background: rgb(235, 235, 235);
      border: 1px solid rgb(204, 204, 204);
      top: 0;
      margin-top: 0;
      &::after {
        font-size: 12px;
      }
    }
  }
</style>